Abstract

We have developed a novel bistatic polarization‐modulated nephelometer that probes a medium enabling insitumeasurement of angle‐ and polarization‐dependent light scattering through a planar interface. This is particularly important for media with a planar interface such as sea ice but also for media in which measurements at great distance or depth, e.g., the atmosphere, are desirable. The instrument sits directly and noninvasively on the planar surface of the scattering medium. Light from a laser beam is directed into the medium and the scattered light is detected by analyzer optics. The angle of both the laser and detector beams in the medium can be varied continuously. Alternating current polarimetry is used to obtain phase function and polarization information of the scattered light. Measurements from this instrument of scattering from monodisperse polystyrene (latex) spheres in the laboratory are in good qualitative agreement with the results of Mie calculations and measurements made with a conventional monostatic nephelometer. This instrument has also been used to make preliminary investigations of scattering in sea ice in Pt. Barrow, Alaska.